Which cuff size and placement are recommended for upper-arm blood pressure measurement in adults?

• A. A cuff with bladder width about 40% of arm circumference and bladder length about 80%; center the cuff over the brachial artery with the lower edge about 1 inch (2.5 cm) above the antecubital fossa; keep the arm at heart level with the patient seated and back supported.
• B. Cuff bladder width about 60% of arm circumference and length about 120%; center the cuff over the radial artery; lower edge at the elbow; arm resting on the chair arm.
• C. Cuff bladder width about 20% of arm circumference and length about 40%; place cuff above the shoulder; arm held above heart level.
• D. Cuff bladder width about 50% of arm circumference and length about 90%; center over the femoral artery; lower edge at the groin.

Answer: (C)

Accurate upper-arm blood pressure relies on using a cuff that fits the arm well and is placed over the brachial artery at the correct position. The bladder should be about 40% of the arm’s circumference in width and roughly 80% in length. This sizing ensures the cuff can occlude the artery adequately without over- or underestimating the pressure.

Center the cuff over the brachial artery so the artery sits under the middle of the bladder, and place the lower edge about 2.5 cm (1 inch) above the elbow crease (antecubital fossa). The arm should be supported at heart level with the patient seated and the back supported.

These details matter because a cuff that’s too narrow or too short can falsely elevate readings, while a cuff that’s too wide or placed away from the brachial artery or at the wrong height can give unreliable results. Placing the cuff above the shoulder or on the thigh or femoral region would measure a different artery or be out of the proper anatomical context, leading to incorrect values.